I want to use both security options AND add a signature. I want to use a PW for opening the document, a password for changing the document, and add a signature. Is that even doable? If so, in what order and when do i save it - between each step or after all steps? No matter what I try, I can only get 2 out of 3.

Product in use is Adobe Acrobat 9.5.5 so I won't need answers for techniques in Adobe DC.